SOLUTION: A popular retail store knows that the purchase amounts by its customers is a random variable that follows a normal distribution with a mean of $30 and a standard deviation of $9.

Question 721275: A popular retail store knows that the purchase amounts by its customers is a random variable that follows a normal distribution with a mean of $30 and a standard deviation of $9.
What is the probability that a randomly selected customer will spend less than $15 at this store? Answer rounded to 4 decimal place.

Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
A popular retail store knows that the purchase amounts by its customers is a random variable that follows a normal distribution with a mean of $30 and a standard deviation of $9.
What is the probability that a randomly selected customer will spend less than $15 at this store? Answer rounded to 4 decimal place.
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z(15) = (15-30)/9 = -15/9 = -1.6667
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P(x < 15) = P(z < -1.6667) = normalcdf(-100,-1.6667) = 0.0478
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Cheers,
Stan H.
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